Light source control device and image forming apparatus

Abstract

A light source control device, includes circuitry to: apply a threshold current, a first emission current, and a first correction current to a light source to drive the light source to emit light to form a first pixel, and apply the threshold current, a second emission current, and a second correction current to the light source to drive the light source to emit light to form a second pixel, wherein the circuitry calculates a value of the second correction current by multiplying a value of the first correction current by a ratio of a value of the second emission current to a value of the first emission current, the value of the second emission current being greater than the value of the first emission current.

What is claimed is: 
     
       1. A light source control device, comprising circuitry to:
 apply a threshold current, a first emission current, and a first correction current to a light source to drive the light source to emit light to form a first pixel, the first correction current correcting the first emission current during application of the first emission current to the light source; and 
 apply the threshold current, a second emission current, and a second correction current to the light source to drive the light source to emit light to form a second pixel, the second correction current correcting the second emission current during application of the second emission current to the light source, 
 wherein the circuitry calculates a value of the second correction current by multiplying a value of the first correction current by a ratio of a value of the second emission current to a value of the first emission current, the value of the second emission current being greater than the value of the first emission current. 
 
     
     
       2. The light source control device according to  claim 1 , wherein the value of the first emission current and the value of the first correction current are set based on a feedback signal corresponding to light quantity of the light emitted from the light source. 
     
     
       3. The light source control device according to  claim 2 ,
 wherein the feedback signal corresponds to a signal obtained by integrating electric signals output from a photodetector that detects the light emitted from the light source. 
 
     
     
       4. The light source control device according to  claim 2 , wherein the circuitry further applies a charge current to the light source immediately before applying the first emission current or the second emission current to the light source. 
     
     
       5. The light source control device according to  claim 4 , wherein a value of the charge current is fixed. 
     
     
       6. The light source control device according to  claim 4 , wherein the circuitry completes charging of a parasitic capacitance in the light source and a circuit connected to the light source with the charge current. 
     
     
       7. An image forming apparatus comprising:
 the light source controlling device according to  claim 1 ; 
 an image bearer on which a latent image is written according to light emission of the light source; 
 a developing device to supply toner to the latent image written on the image bearer to develop the latent image into a visible toner image; 
 a transfer device to transfer the visible toner image, into which the latent image is developed by the developing device, onto a recording medium; and 
 a fixing device to fix the toner image transferred by the transfer device onto the recording medium. 
 
     
     
       8. A method of controlling a light source, comprising:
 applying a threshold current, a first emission current, and a first correction current to a light source to drive the light source to emit light to form a first pixel, the first correction current correcting the first emission current during application of the first emission current to the light source; and 
 applying the threshold current, a second emission current, and a second correction current to the light source to drive the light source to emit light to form a second pixel, the second correction current correcting the second emission current during application of the second emission current to the light source, 
 wherein the second correction current has a value calculated by multiplying a value of the first correction current by a ratio of a value of the second emission current to a value of the first emission current, the value of the second emission current being greater than the value of the first emission current. 
 
     
     
       9. A non-transitory recording medium storing a plurality of instructions which, when executed by one or more processors, cause the processors to perform a method comprising:
 applying a threshold current, a first emission current, and a first correction current to a light source to drive the light source to emit light to form a first pixel, the first correction current correcting the first emission current during application of the first emission current to the light source; and 
 applying the threshold current, a second emission current, and a second correction current to the light source to drive the light source to emit light to form a second pixel, the second correction current correcting the second emission current during application of the second emission current to the light source, 
 wherein the second correction current has a value calculated by multiplying a value of the first correction current by a ratio of a value of the second emission current to a value of the first emission current, the value of the second emission current being greater than the value of the first emission current.